After entering the ICU, the subjects who meet the standards will undergo a full-body physical examination and basic vital signs assessment and monitoring, which mainly include specialized examinations of the nervous system, multimodal brain function testing, respiratory system monitoring and management, hemodynamic monitoring, and APACHEⅡ Score, GCS score, and perform routine general circulation, breathing management, sedation and analgesia management, temperature management, osmotic pressure management, lumbar puncture pressure measurement